forgejo/docs/content/doc/development/oauth2-provider.en-us.md

date	title	slug	weight	toc	draft	aliases	menu
2023-06-01T08:40:00+08:00	OAuth2 provider	oauth2-provider	41	false	false	/en-us/oauth2-provider	sidebar parent name weight identifier development OAuth2 Provider 41 oauth2-provider

OAuth2 provider

Table of Contents

{{< toc >}}

Gitea supports acting as an OAuth2 provider to allow third party applications to access its resources with the user's consent. This feature is available since release 1.8.0.

Endpoints

Endpoint	URL
OpenID Connect Discovery	/.well-known/openid-configuration
Authorization Endpoint	/login/oauth/authorize
Access Token Endpoint	/login/oauth/access_token
OpenID Connect UserInfo	/login/oauth/userinfo
JSON Web Key Set	/login/oauth/keys

Supported OAuth2 Grants

At the moment Gitea only supports the Authorization Code Grant standard with additional support of the following extensions:

• Proof Key for Code Exchange (PKCE)
• OpenID Connect (OIDC)

To use the Authorization Code Grant as a third party application it is required to register a new application via the "Settings" (/user/settings/applications) section of the settings. To test or debug you can use the web-tool https://oauthdebugger.com/.

Scopes

Gitea supports the following scopes for tokens:

Name	Description
(no scope)	Grants read-only access to public user profile and public repositories.
repo	Full control over all repositories.
repo:status	Grants read/write access to commit status in all repositories.
public_repo	Grants read/write access to public repositories only.
admin:repo_hook	Grants access to repository hooks of all repositories. This is included in the repo scope.
write:repo_hook	Grants read/write access to repository hooks
read:repo_hook	Grants read-only access to repository hooks
admin:org	Grants full access to organization settings
write:org	Grants read/write access to organization settings
read:org	Grants read-only access to organization settings
admin:public_key	Grants full access for managing public keys
write:public_key	Grant read/write access to public keys
read:public_key	Grant read-only access to public keys
admin:org_hook	Grants full access to organizational-level hooks
admin:user_hook	Grants full access to user-level hooks
notification	Grants full access to notifications
user	Grants full access to user profile info
read:user	Grants read access to user's profile
user:email	Grants read access to user's email addresses
user:follow	Grants access to follow/un-follow a user
delete_repo	Grants access to delete repositories as an admin
package	Grants full access to hosted packages
write:package	Grants read/write access to packages
read:package	Grants read access to packages
delete:package	Grants delete access to packages
admin:gpg_key	Grants full access for managing GPG keys
write:gpg_key	Grants read/write access to GPG keys
read:gpg_key	Grants read-only access to GPG keys
admin:application	Grants full access to manage applications
write:application	Grants read/write access for managing applications
read:application	Grants read access for managing applications
sudo	Allows to perform actions as the site admin.

Client types

Gitea supports both confidential and public client types, as defined by RFC 6749.

For public clients, a redirect URI of a loopback IP address such as http://127.0.0.1/ allows any port. Avoid using localhost, as recommended by RFC 8252.

Examples

Confidential client

Note: This example does not use PKCE.

1. Redirect the user to the authorization endpoint in order to get their consent for accessing the resources:

   https://[YOUR-GITEA-URL]/login/oauth/authorize?client_id=CLIENT_ID&redirect_uri=REDIRECT_URI&response_type=code&state=STATE
   

   The CLIENT_ID can be obtained by registering an application in the settings. The STATE is a random string that will be sent back to your application after the user authorizes. The state parameter is optional, but should be used to prevent CSRF attacks.

   

   The user will now be asked to authorize your application. If they authorize it, the user will be redirected to the REDIRECT_URL, for example:

   https://[REDIRECT_URI]?code=RETURNED_CODE&state=STATE
   

2. Using the provided code from the redirect, you can request a new application and refresh token. The access token endpoint accepts POST requests with application/json and application/x-www-form-urlencoded body, for example:

   POST https://[YOUR-GITEA-URL]/login/oauth/access_token
   

   {
     "client_id": "YOUR_CLIENT_ID",
     "client_secret": "YOUR_CLIENT_SECRET",
     "code": "RETURNED_CODE",
     "grant_type": "authorization_code",
     "redirect_uri": "REDIRECT_URI"
   }
   

   Response:

   {
     "access_token": "eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJnbnQiOjIsInR0IjowLCJleHAiOjE1NTUxNzk5MTIsImlhdCI6MTU1NTE3NjMxMn0.0-iFsAwBtxuckA0sNZ6QpBQmywVPz129u75vOM7wPJecw5wqGyBkmstfJHAjEOqrAf_V5Z-1QYeCh_Cz4RiKug",
     "token_type": "bearer",
     "expires_in": 3600,
     "refresh_token": "eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJnbnQiOjIsInR0IjoxLCJjbnQiOjEsImV4cCI6MTU1NzgwNDMxMiwiaWF0IjoxNTU1MTc2MzEyfQ.S_HZQBy4q9r5SEzNGNIoFClT43HPNDbUdHH-GYNYYdkRfft6XptJBkUQscZsGxOW975Yk6RbgtGvq1nkEcklOw"
   }
   

   The CLIENT_SECRET is the unique secret code generated for this application. Please note that the secret will only be visible after you created/registered the application with Gitea and cannot be recovered. If you lose the secret, you must regenerate the secret via the application's settings.

   The REDIRECT_URI in the access_token request must match the REDIRECT_URI in the authorize request.

3. Use the access_token to make API requests to access the user's resources.

Public client (PKCE)

PKCE (Proof Key for Code Exchange) is an extension to the OAuth flow which allows for a secure credential exchange without the requirement to provide a client secret.

Note: Please ensure you have registered your OAuth application as a public client.

To achieve this, you have to provide a code_verifier for every authorization request. A code_verifier has to be a random string with a minimum length of 43 characters and a maximum length of 128 characters. It can contain alphanumeric characters as well as the characters -, ., _ and ~.

Using this code_verifier string, a new one called code_challenge is created by using one of two methods:

• If you have the required functionality on your client, set code_challenge to be a URL-safe base64-encoded string of the SHA256 hash of code_verifier. In that case, your code_challenge_method becomes S256.
• If you are unable to do so, you can provide your code_verifier as a plain string to code_challenge. Then you have to set your code_challenge_method as plain.

After you have generated this values, you can continue with your request.

1. Redirect the user to the authorization endpoint in order to get their consent for accessing the resources:

   https://[YOUR-GITEA-URL]/login/oauth/authorize?client_id=CLIENT_ID&redirect_uri=REDIRECT_URI&response_type=code&code_challenge_method=CODE_CHALLENGE_METHOD&code_challenge=CODE_CHALLENGE&state=STATE
   

   The CLIENT_ID can be obtained by registering an application in the settings. The STATE is a random string that will be sent back to your application after the user authorizes. The state parameter is optional, but should be used to prevent CSRF attacks.

   

   The user will now be asked to authorize your application. If they authorize it, the user will be redirected to the REDIRECT_URL, for example:

   https://[REDIRECT_URI]?code=RETURNED_CODE&state=STATE
   

2. Using the provided code from the redirect, you can request a new application and refresh token. The access token endpoint accepts POST requests with application/json and application/x-www-form-urlencoded body, for example:

   POST https://[YOUR-GITEA-URL]/login/oauth/access_token
   

   {
     "client_id": "YOUR_CLIENT_ID",
     "code": "RETURNED_CODE",
     "grant_type": "authorization_code",
     "redirect_uri": "REDIRECT_URI",
     "code_verifier": "CODE_VERIFIER",
   }
   

   Response:

   {
     "access_token": "eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJnbnQiOjIsInR0IjowLCJleHAiOjE1NTUxNzk5MTIsImlhdCI6MTU1NTE3NjMxMn0.0-iFsAwBtxuckA0sNZ6QpBQmywVPz129u75vOM7wPJecw5wqGyBkmstfJHAjEOqrAf_V5Z-1QYeCh_Cz4RiKug",
     "token_type": "bearer",
     "expires_in": 3600,
     "refresh_token": "eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJnbnQiOjIsInR0IjoxLCJjbnQiOjEsImV4cCI6MTU1NzgwNDMxMiwiaWF0IjoxNTU1MTc2MzEyfQ.S_HZQBy4q9r5SEzNGNIoFClT43HPNDbUdHH-GYNYYdkRfft6XptJBkUQscZsGxOW975Yk6RbgtGvq1nkEcklOw"
   }
   

   The REDIRECT_URI in the access_token request must match the REDIRECT_URI in the authorize request.

3. Use the access_token to make API requests to access the user's resources.